Improvement in joiners  clamps



UNITED S'rA'IE-s GUsrAv A. NAUMANN, OE ST. LOUIS, MISSOURI, ASSIGNOE To EUETEEE, OE SAME PLAOE.y

JAOOB IMPROVEMENT IN JOINRS CLAMPS.

Specilication forming part of Letters Patent No. 179,942, dated July 18, 1876; application file l April 28, 1876.

To all whom it may concern:

Be it known that I, GUsrAv A. NAUMANN, of St. Louis, Missouri, have invented an Improvement in J oiuers Clamps, of which the- .following is a specification:

' This invention is an improvement on patent for joiners7 clamp granted to meMarch 14, 1876, No. 174,838. A

As is well known, the two jaws of a joiners clamp are required to have all the strength possible, so as to be durable for both Operation and use. Also, in clamps of this chap acter, in which the movable jaw is rapidly to operate.

Ot' the drawing, Figure 1 is a Sectional side elevation. Fig. 2 is a detail side view of operatin g parts that lock and unlock the hand-screws. Fig. 3 is a detail perspective, showing construction of the sleeve and its pivf oted Swingin g arm. i

A is the stationary jaw B, its movable or adj ustable jaw.

I cast two sleeves, C C, one for the passage ot' the front and the other for` the rear hand-screw. These sleeves have at their one end a flange, c, which limits their insertion into thejaw, as shown in Figs. 1,2.

The strain of the hand screws being reversed-wiz., the front one acting downward in the movable jaw-I insert the sleeve C from above, the flange c thereof resting on top of the jaw.

The strain of the rear haudscrew being upward in the movable jaw, I insert the sleeve G from below, and its llange c similarly preventsit from being drawn-through the jaw.

I provide the following devices, in connection with the sleeves C C', to lock and unlock the screws, or secure the adjustable jaw in position: D and D are swinging arms, ofthe form shown in Figs.l and3, and haviugthe-threads d. These'arms are pivoted in slots c', formed or cast in the sleeves C C.r

Thel arm D is pivoted in the Sleeve G at d l, while the arm D is pivoted on the sleeve C' at d2. vantagethat, after they once engage with the screws, the strain bearing on the arms will,`

E, is provided on top of the movable jaw, of

the shape shown inFigs. l and 2, and formed. with a triggershaped stud on top for theoperator to take hold of. This slide has at its front end a hook, e, catching the arm D through l an eye, d5. The other end of the ,slide has a pin, c1, engaging into a similar eye, d6, in the arm D', and a shoulder, c2, pressing against this point of the arm D. v

Ey drawing uns slide E back, its 1100156611-v gages the arm D. This arm, being pivoted below, draws said arm'back with it and out of engagement with its screw, at the'same time compressing its spring. The pin el at the other end ofthe slide E, engaging the arm D by means of its shoulder c2, pushes this end ot' the arm along with it; but this latter arm being pivoted above, its lower end is swung forward and out of engagement with its screw, at the same time compressing its spring, and thus the parts Stand inthe position shown in Fig. 2. l

By loosening the slide E the springs return the parts to their original locked position.

As seen in the drawing,"but very little of the solid material is cut away from the jaw; also, no screws are required to secure the parts in position 5 and, from the construction, it

will be seen that the improvements here pre.

PATENT OFFICE.

The pivoting of' the arms gives the adsented possess the further advantages of In testimony of said invention I havehereeheapness, durability, and effective operation. unto set my hand.

Vhat I clim is` The combination of aswinging arm, D, hav- GUSTAV A. NAUMANN. ing threads d, pvoted to a sleeve, C, having slot c and shoulder d4, in combination with Witnesses: a hand-screw of a joiners clamp, to operate WILLIAM W. HERTHEL, as set forth. Clins. F. MEIsNER.

Agli 

